Disclosed are an apparatus and a method for correcting data through system analysis for each period in the field of an energy management system (EMS). An apparatus for correcting acquired data includes a topology processing (TP) unit and at least one system analyzing unit. The TP unit acquires data including circuit breaker information from a supervisory control and data acquisition (SCADA) system. The at least one system analyzing unit stores data for performing state estimation with respect to the data output from the TP unit, and processes the stored data according to a predetermined period. In the apparatus, the system analyzing unit is classified into at least one data processing group according to the data processing period.